Triggered square wave voltage generator



Sept. 11, 1951 H. P. STABLER TRIGGERED SQUARE WAVE VOLTAGE GENERATORFiled Sept. 24, 1946 M959 R N228. mm mm a v .m :EZGEQ NN ms 3 wo 5o wwzA M252 D R m N. o H J 2 m J wm 8! 5&3

ATTORN EY Patented Sept. 11,1951

TRIGGERED SQUARE WAVE VOLTAG GENERATOR Howard P. Stabler,WilliamstowmMass assignor, by mesne assignments, to the United States ofAmerica as represented by the Secretary of the Navy ApplicationSeptember 24, 194G,-Serial No. 699,043

1 This invention relates to square wave voltage generator and moreparticularly to triggered square wave voltage generators having anoutput with an adjustable maximum value and an independently adjustablepeak to peak value.

'This application is a continuation-in-part of my copending applicationentitled V-Beam Height Indicator Serial No. 699,044, filed September 24,1946, and hereinafter referred to as the parent application.

In the parent application a circuit is required that will produce twoadjustable azimuth markers on the screen of a cathode ray tube. A squarewave voltage, adjustable in maximum value and independently adjustablein peak to peak value, having a frequency equal to one half the pulserepetition rate of the radar transmitter and applied to the azimuthdeflection plates of the cathode ray tube will produce these desiredazimuth markers. As disclosed in the parent application this square wavevoltage is applied to the azimuth deflection plates of the cathode raytube during periods when the azimuth sweep voltage is not present.

It is therefore a primary object of this invention to provide atriggered square wave voltage generator.

Another object of this invention is to provide a triggered square wavevoltage generator with an output adjustable in average value and peak topeak value.

A further object is to provide a triggered square wave voltage generatorwith an output having an adjustable maximum value and an independentlyadjustable peak to peak value.

These and other objects will be apparent to those skilled in the artfrom the following specification when taken with the accompanyingdrawing which is a schematic diagram of one embodiment thereof.

Referring to the diagram resistors II and I2, rheostats l3 and I4, andvoltage regulator electron tube l with its associated load constitute avoltage divider between the positive voltage supply available atterminal 20 and the negative voltage supply at terminal 2|. Decouplingcondenser 22 is connected between the negative voltage supply terminal2I and ground. Voltage regulator electron tube 15 has its plateconnected to the slidable contact arm of rheostat l3 and its cathodeconnected to the slidable contact arm of rheostat l4 and has filtercondenser 23 connected across between its anode and cathode. Theslidable arms of rheostats I3 and M are so arranged mechanically andelectrically that the difference 7 Claims. (01. 250-27 of potentialbetween them always remains a fixed amount although the absolute voltageat the sliders may be changed by movement of the sliders along theresistance of the respective rheostats as indicated by dotted line 26.

Triode electron tubes 24 and 25 are connected as a cathode-coupledflip-flop multivibrator circuit with the plate voltage supply obtainedfrom voltage regulator tube 55. The cathodes of triodes 24 and 25 areconnected together and then through resistor 30 tothe cathode of voltageregulator tube i5, the plate. of triode 24 is connected through resistor3| to the plate of voltage regulator tube 15, and the plate of triode 25is connected through resistor 32 to the plate of voltage regulator tubeI5. The grid of triode 24 is connected through the parallel combinationof condenser 33 and resistor 34 to the plate of triode 25 and throughresistor 35 to the cathode of voltage regulator tube l5. The grid oftriode 25 is connected through the parallel combination of resistor 48and condenser 41 to the plate of triode 24 and through resistor 42 tothe cathode of voltage regulator tube [5.

Positive range voltage gate input terminal 43 is connected to groundthrough input resistor 44 and through the series combination of peakingcondenser 45 and limiting resistor 56 to the grid of triode electrontube 5!. Triode 5| also has its grid connected through isolatingresistor 52 to the positive voltage supply at terminal 20, its plateconnected through plate load resistor 53 to terminal 20, and its cathodegrounded. The plate of triode 5| is coupled through condenser 54 to thegrid of triode 24 and through condenser 55 to the grid of triode 25.

Triode electron tubes and BI have their cathodes connected together andthrough resistor 62 to the cathode of voltage regulator tube 15. Thegrid of triode 60 is connected to the grid of triode 25 and the plate oftriode 60 is connected through plate load resistor 63 to the plate ofVoltage regulator tube 1.5. Triode 6| has its grid connected to the gridof triode 24 and its plate connected through the entire resistance ofpotentiometer 64, as a plate load resistance, to the plate of voltageregulator tube 15. contact arm of potentiometer 54 is connected to thegrid of triode electron tubefili which is connected as a cathodefollower with its plate connected directly to the positive voltagesupply at terminal 2E! and its cathode connected through cathode loadresistor 10 to ground. Square wave voltage output terminal H isconnected to the cathode of triode 65.

The Y In the operation of this embodiment of the invention, the positiverange voltage gate applied at terminal 43 produces at its trailing edgea positive voltage pulse output at the plate of triode 5|. This positivevoltage pulse is applied simultaneously to the grids of triodes 24 and25 which are connected as a flip-flop multivibrator having one tube in aconducting state and the other in a non-conducting state. The positivevoltage pulse when applied to the grid of the non-iconducting tube,raises the grid voltage to a sufiicien't voltage level to cause thenon-conducting tube to become conducting. As triodes 24 and 25 areconnected as a flip-flop multivibrator, the triggering of one triodefrom the non-conducting to the conducting state causes the other triodeto be changed from the conducting to the nonconducting state bymultivibrator action.

The efiect of this multivibrator action is such that a substantiallysquare wave voltage is produced at the grid of triode 24 and triode 25.This square wave voltage is then coupled from the gridof'triode 25 tothe grid of triode 60 and from the grid of triode 24 to the grid oftriode 5| alternately changing triodes 60 and El from a non-conductingto aconducting state. The voltage output obtained-at the arm ofpotentiometer 64 will, therefore, be arsquare wave voltage due to thealternate conducting and non-conducting state-of triode BI. This squarewave voltage is coupled to the grid of triode 65 and is available atsquare wave voltage output terminal H. Triode 60 functions in thecircuit to maintain an approximately constant load upon voltageregulator tube IE to prevent the discharge in voltage regulator tube l5from beingextinguished with resultant large swings in voltage outputduring the time when triode BI is non-conducting.

The maximum value of the square Wave voltage -output from terminal H isobtained when triod BI is non-conducting and is substantially equal tothe voltage appearing at the variable armcf rheostat l3, and theminimumvalue is obtained when triode- 6 I is conductingand is substantiallyequal to the maximumzvalue of the square wave voltage output less theresistance drop in potentiometer '64 between the sliding contact arm andthe end of theresistance connected to theplate of vvoltage regulatortube l5.

It may, therefore, .be :seen that the vmaximum value of the square wavevoltage output is dependent-upon the setting of rheostats I3 and M, andthe minimum value is dependent upon the combined setting of the slidingarm of potentiometer B4 and the rheostats I3 and M.

As a complete cycle of the square wave voltage output at terminal Hresults from trigger pulses received from two positive voltage rangegates, the frequency of the square'wave voltage output is one half ofthe :radar transmitter repetition rate with one radar range sweepoccurring during each half cycle of the squarewave voltage output.

In the use of this squarewave voltage generator asa marker generator.for use in measuring the distance:between twopoints of a'cathode raytube presentation, rheostats I3 and .I4 are simultaneouslyv manipulateduntil the marker corresponding to the maximum value of the square wavevoltageis aligned with one of .the two points,

and then potentiometer :is adjusted by a calibratedknob (not shown)until the other marker is aligned with the second point. The distancebetween the two points on the cathode ray tube presentation is thenshown directly on the calibrated knob of potentiometer 64.

The invention described in the foregoing speci fication need not belimited to the details shown which are considered to be illustrative ofthe embodiment of the invention most applicable to use with theinvention disclosed in the parent application which is considered to beillustrative of one form that the invention may take. The scope of theinvention is defined by the appended claims.

What is claimed is:

l. A triggered square wave voltage generator having an output voltageadjustable in maximum and peak to peak values comprising, a firstelectron tube having at least a cathode, an anode, and control grid, apositive voltage supply, a negative voltage supply, first and secondresistors, first and second rheostats, a second electron tube having atleast a cathode, and an anode, said second electron tube serving as avoltage regulator and having its cathode connected through said firstrheostat and said first resistor to said negative voltage supply and itsanode connected through said second rheostat and said second resistor tosaid positive voltage supply, the contact arms of said first and secondrheostats being mechanically coupled so that the voltage from cathode toanode of said second electron tube remains constant despite changes inthe absolute voltage of the anode and cathode of said second electrontube due to movement of said contact arms of said first and secondrheostats, a third resistor connected between the cathode of said firstelectron tube and the cathode of said second electron tube, apotentiometer, the resistance of said potentiometer connected betweenthe anode of said first electron tube and the anode of said secondelectron tube, a source of positive voltage control pulses, meansoperated by said positive voltage control pulses to cause said firstelectron tube to be conducting during alternate positive voltage controlpulses and nonconducting during intervening positive voltage controlpulses, and means .to obtain a voltage output from the contact arm ofsaid potentiometer, said voltage output being a square wave due to thealternate conduction and non-conduction of said first electron tube, themaximum value of said square Wave being dependent upon the setting ofsaid first and second rheostats and the peak to peak value beingdependent solely upon the setting of said contact arm of saidpotentiometer.

2. A triggered square wave voltage generator having an output adjustablein maximum and peak to peak voltage values, comprising means forproducing a constant predetermined difference voltage between first andsecond potentials, means to adjust the absolute value of saidpotentials, a source of positive voltage gates, a first electron tubehaving at least a cathode, an anode, and a control grid, a firstcondenser, a first resistor, said firstcondenser and first resistorconnected in series between said source of positive voltage gates andthe control grid of said first electron tubeLa positive voltage source,a second resistor connecting the grid of said first electron tube tosaidpositive voltage source, a third resistor connected between the:plate of said'first electron tube andsaid positive voltage source, thecathode .of said first electron tube being grounded, a second electrontube having at least a cathode, an anode, and a-control grid, meansoperated by the output from said first electron tube to cause saidsecond electron tube to be alternately conducting and non-conducting, apotentiometer, the resistance of said potentiometer being connectedbetween the plate of said second electron tube and to one side of saidconstant difference of potential, a third electron tube having at leasta cathode, an anode and a control grid, the control grid of said thirdelectron tube being connected to the contact arm of said potentiometer,the plate of said third electron tube connected to said positive voltagesupply, an output terminal, and a fourth resistor, said fourth resistorbeing connected between the oathode of said third electron tube andground, said output terminal being connected directly to the cathode ofsaid third electron tube.

3. A triggered square wave voltage generator having an output adjustablein maximum and peak to peak values, comprising a positive voltagesupply,'a negative voltage supply, first and second resistors, first andsecond rheostats, a first electron tube connected as a voltage regulatortube having at least a cathode and an anode, the cathode of said firstelectron tube being connected through said first rheostat and said firstresistor to said negative voltage supply and the anode being connectedthrough said second rheostat and said second resistor to said positivevoltage supply, the sliding contact arms of said first and secondrheostats being mechanically coupled so that the anode to cathodevoltage of said first electron tube remains constant despite changes inposition of said sliding contact arms of said first and secondrheostats, a first condenser connected between the anode and cathode ofsaid first electron tube, second and third electron tubes each having atleast a cathode, an

anode, and a control grid, said second and third electron tubes beingconnected as a flip-flop multivibrator, third and fourth resistorsconnecting the anode of said second and third electron tubesrespectively to the anode of said first electron tube, fifth and sixthresistors connecting the control grids of said second and third electrontubes respectively to the cathode of said first electron tube, a seventhresistor common to the cathodes of said second and third electron tubesconnecting them to the cathode of said first electron tube, a secondcondenser connected between the anode of said second electron tube andthe control grid of said third electron tube, a third condenserconnected between the anode of said third electron tube and the controlgrid of said second electron tubes, an eighth resistor connected inparallel with said second condenser, a ninth resistor connected inparallel with said third condenser, a source of positive voltage rangegates, means operated by said positive voltage range gates to formpositive voltage triggers, fourth V and fifth condensers to couple saidpositive voltage triggers to the control grid of said second and thirdelectron tubes respectively, fourth and fifth electron tubes each havingat least a cathode, an anode, and a control grid, the control grids ofsaid second and fourth electron tubes being connected together and thecontrol grids of said third and fifth electron tubes being connectedtogether, a tenth resistor, the cathodes of said fourth and fifthelectron tubes being joined and connected through said tenth resistor tothe cathode of said first electron tube, an eleventh resistor connectingthe anode of said fourth electron tube to the anode of said firstelectron tube, a potentiometer, the resistance of said potentiometerbeing connected between the anodes of said fifth and first electrontubes, and means for obtainin a voltage output from the sliding contactarm of said lpotentiometen'said voltage output being a square wave; i

4. A triggered squarev wave voltage generator having an outputadjustable in maximum and peak to peak values comprising, an electrontubehaving at least an anode, a-cathode and a control grid, at source ofunidirectional potentials, means for producing a regulated predetermineddifference voltagebetween two potentials from said source, means foradjusting the absolute, values of said potentials, said regulateddifference voltage being adapted for use as the anode voltage supply forsaid electron tube, a potentiometer, the resistance of saidpotentiometer being connected between the plate of said electron tubeand one terminal of said difference voltage, a source of positivevoltage control pulses, a multivibrator triggered by said control pulsesfor mak-; ing said electron tube alternately conductive and,non-conductive during successive control pulses, and means for obtaininga voltage output from the contact arm of said potentiometer, saidvoltage output being in the form of a square Wave having the maximumvoltage adjustable by said means for adjusting the absolute value ofsaid potentials and the peak to peak voltage independently adjustable bythe contact arm of said potentiometer.

5. -A triggered square wave voltage generator having an outputadjustable in maximum and peak to peak values comprising, first andsecond electron tubes each having at least an anode, a cathode and acontrol grid, a source of unidirectional potentials, means for producinga regulated predetermined difference voltage between two potentials fromsaid source, means for adjusting the absolute value of said potentials,said regulated difference voltage being adapted for use as the anodevoltage supply for said electron tubes, a potentiometer, the resistanceof said potentiometer being connected between the plate of said firstelectron tube and one terminal of said difference voltage, a source ofpositive voltage control pulses, a multivibrator energized from saiddifference voltage and triggered by said control pulses for making saidelectron tubes alternately conducting and nonconducting duringsuccessive control pulses, said alternate conducting and nonconductingfirst and second electron tubes acting to provide a constant load onsaid regulated difference voltage, and means for obtaining a voltageoutput from the contact arm of said potentiometer, said voltage outputbeing in the form of a square wave having the maximum voltage adjustableby said means for adjusting the absolute value of said potentials andthe peak to peak voltage independently adjustable by the contact arm ofsaid potentiometer.

6. A triggered square wave voltage generator having an adjustablemaximum value and an independently adjustable peak to peak valuecomprising, a source of unidirectional potentials, means for producing aregulated diiference voltage between two potentials from' said source,means for adjusting the absolute value of said potentials, a source ofpositive voltage control pulses, a driven multivibrator energized bysaid regulated difference voltage and responsive to positive pulses fromsaid source, an overdriven amplifier also energized from said regulateddifference voltage and responsive to the output wave form of saidmultivibrator for producing a substantially square wave output voltage,a cathode follower circuit energized from said potentiallsource andresponsive .to the output of said amplifier to yield a square waveoutput voltage, means for adjusting the amplitude of voltage fed fromsaid amplifier to said cathode follower to adjust the peak to peak valueof said cathode follower square wave output voltage, said cathodefollower being biased by variation of the absolute value of saidpotentials from said source to vary the maximum value of said squarewave output voltage.

=7. A triggered square wave voltage generator having an adjustablemaximum value and an independently adjustable peak to peak valuecomprising, -.a source of unidirectional potentials, means for producinga regulated difference voltage between two potentials from said source,means for adjusting the absolute value of said potentials, an overdrivenamplifier including first and. second electron tubes each having atleast an anode, a cathode and a control grid, means for energizing saidamplifier from said regulated difference voltage, a potentiometer, theresistance of said potentiometer being connected between the plate ofsaid first electron tube and one terminal of said difference voltage, asource of positive voltage control pulses, a driven multivibratorenergized from said regulated difference voltage and triggered by saidpositive voltage control pulses for making said first and sec- 0ndelectron tubes alternately conducting and nonconducting duringsuccessive control pulses to produce substantially a square wave outputvoltage, said alternately conducting and nonconducting first and. secondelectron tubes acting to provide a constant load on said regulateddifference voltage, a cathode follower circuit energized from saidpotential source and responsive to the output of said amplifier to yielda square wave output voltage, means for adjusting the amplitude ofvoltage fed from said amplifier to said cathode follower to adjust thepeak to peak value of said cathode follower square wave .output voltage,said cathode follower "being biased by variation of the absolute valueof said potentials from said source to vary the maximum value of saidsquare Wave output voltage.

HOWARD P. STABLER.

REFERENCES CITED The following references are of record in the file ofthis patent:

UNITED STATES PATENTS Number Name Date 1,979,484 Mathes Nov. 6, 19342,286,377 Roberts June 16, 1942 2,403,934 Koenig, Jr., et a1. July 16,1946

